[GHC] #13458: Panic with unsafeCoerce and -dcore-lint

[GHC]

#13458: Panic with unsafeCoerce and -dcore-lint
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        Reporter:  dfeuer            |                Owner:  goldfire
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Compiler (Type    |              Version:  8.1
  checker)                           |             Keywords:
      Resolution:                    |  LevityPolymorphism
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 I'm uncomfortable with restricting the type of `unsafeCoerce#`. What if
 someone wants to do something really dirty, like cast a `Float#` into a
 `Word#` just to see the bits? This would be prohibited by comment:10.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13458#comment:11>
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